Indicating and plugging apparatus for oil wells



Dec. 3, 1957 RAJ. STEGEMEIER ETAL INDICATING AND PLUGGING APPARATUS FOROIL WELLS 2 Sheets-Shet 1 Filed July 21, 1955 'IIIIIIIIII LI, WM% ##4 1J m 1 Z #0 d Z7, a

Irma ix 2,814,947 INDICATING AND PLUGGING APPARATUS FOR OIL WELLS FiledJuly 21, 1955 De. 3, 1957 R. J. STEGEMEIER ET AL 2 Sheets-Sheet 2 UnitedStates Patent 2,814,947 Patented Dec. 3, 1957 nice INDICATING ANDPLUGGING APPARATUS FOR 01L WELLS Richard J. 'Stegemeier and George P.Maly, Fullerton, Calif assignors to Union Oil Company of California, LosAngeles, Calif, a corporation of California Application July 21, 1955,Serial No. 523,476

13 Claims. (Cl. 73-155) This invention relates to a novel indicating andplugging apparatus for use in oil wells, and in particular concerns adevice or tool adapted to being positioned within a well bore for thepurpose of determining the location of fluid-producing strata traversedby the bore and/ or for plugging off such strata to prevent the flow offluids into the bore hole.

In many of the oil-producing areas of the world the production of crudeoil from wells is accompanied by the production of water or brine. Welleffluents comprising as much as 90 percent of water or brine and onlypercent of petroleum are by no means uncommon. The cost of raising suchwater or brine to the earths surface and of separating it from the oilrepresents an economic loss, and in many instances the problem ofdisposing of the waste water or brine .is more than one of mereeconomies. In some instances the water-bearing strata lie a considerabledistance above or below the oil-bearing strata, and in such cases theflow of water into the well can be shut off by isolating thewater-bearing strata and plugging them with Portland cement or the likewithout similarly plugging the oil-bearing strata. Such procedure,however, requires accurate information as to the exact point or pointsof water intrusion into the bore, In other instances the oilandwater-bearing strata lie so close together that conventional methods forlocating the two types of strata are incapable of distinguishing betweenthe two, and ordinary cementing procedures result in plugging the oilandwater-bearing strata alike. .It is also occasionally desired to locateand/ or plug off gas-bearing strata, and .the same problems arise inconnection therewith.

It .is accordingly an object of the present invention to provideimproved means for accurately locating fluidbearing strata traversed bya well bore.

Another object is to provide a device adapted to being positioned withina well bore for the purpose of determining accurately the location ofwater bearing strata which are closely associated with oil-bearingstrata.

A further object is to provide a device for selectively plugging olfsubterranean water-bearing strata which are located closely adjacent tooil-bearing strata.

A still further object is to provide a device for indicating theaqueous, oleaginous or gaseous nature of the fluids produced from stratatraversed by a well bore.

Other and related objects will be apparent from the following detaileddescription of the invention, and various advantages not specificallyreferred to herein will be apparent to those skilled in the art uponemployment of the invention inpractice.

We have found that the above objects and attendant advantages may berealized by means of a device or tool which operates on a principle oflaterally dividing a selected portion of the well bore into ap'luralityof isolated increments or sections of relatively short length, each ofwhich sections contains a foraminous material which is sensitive withrespect 'to the various fiuids produced by the well and/or is capable=offorming an impermeable plug when contacted therewith. The termforaminous fluid-sensitive matelial is herein employed to designate aporous solid which undergoes an observable physical or chemical changewhen contacted with a well fluid. As is hereinafter more fully pointedout such a material may take various forms. In employing the apparatusof the invention to determine the location of fluidbearing strata it ispositioned within the well bore opposite the portion of the formationwhich is to be investigated, and the well is thereafter allowed toproduce until conditions of natural flow are attained. The apparatus isthen removed from the well and examination of the fluid-sensitivematerial in each of the isolated sections will establish the aqueous,oleaginous, or gaseous nature of the well fluid which has entered eachof said sections. Since the position which each of said sectionspreviously occupied within the well bore is accurately known, thelocation of the fluid-bearing strata along the length of the portion ofthe bore subjected to investigation can accurately be determined. Whenthe device is employed as a plugging tool it may be allowed to remainpermanently in the bore, the fluid-sensitive material employed in eachsection being one which forms an impermeable plug in those sections intowhich the undesirable fluid has intruded but which remains foraminous inthose sections into which only oil has entered. Other means of employingthe device of the invention are set forth hereinafter.

In the accompanying drawing which forms a part of this specification:Figure 1 schematically illustrates the operating principle of the deviceprovided by the invention; Figure 2 is' a cross-sectional view of oneform which the apparatus may take; Figure 3 is a fragmentary Viewillustrating how the apparatus of Figure 2 is positioned within the wellcasing; Figures 4 and 5 are partial cross-sectional views of anotherform of apparatus within the scope of the invention; and Figures 6 and 7are partial cross-sectional views of still a third form of the device.

Referring now to Figure 1, and with particular reference to use of thedevice to determine the location of water-bearing strata. Bore hole 10is shown extending through subterranean formation 11 and traversingwaterbearing stratum 12, oil-bearing stratum 13, water-bearing stratum14 and oil-bearing stratum 15. Well casing 16 is cemented within thebore by means of cement plug 18, and perforations 17 (formed, forexample, by conventional gun perforation) extend through the walls ofcasing 16 and plug 18. The indicating and plugging tool of the inventionrests within casing 16 on tool support 16a affixed to the inner wall ofcasing 16, and consists essentially of a central vertical conduit 19carrying a plurality of spaced horizontal separators 20 which engage theinner wall of casing 16 at their peripheries forming fluid-tight sealstherewith. Central conduit 19 is provided with perforations 21 locatedbetween each of separators 2t), and the spaces between said separatorsis filled with a water-sensitive material 22. As will readily be seen,positioning the device within the casing effects division of the borehole into a series of isolated vertically stacked chambers or cells,each of which is defined by two of the separators 20, a portion of theinner wall of casing 16, and a portion of the outer wall of centralconduit 19. Each of said cells is filled with water-sensitive material22 and communicates with the formation traversed by the bore via atleast one of the perforations 1'7 and with the interior of conduit '19via at least one of the perforations 21.

In employing the tool illustrated by Figure 1 as an instrument fordetermining the location of water-bearing strata 12 and'l l, the well ispumped dry or, alternatively, is fille'd with :oil or othernon-aqueousliquid. If necessary, superimposed pressure may be applied to preventwell fluids from entering the bore hole while the device is beingpositioned within the bore. The device is then lowered into the casingand positioned opposite the formation to be investigated by suitablepositioning of tool support 16a which may be attached to the inside ofthe casing either before or after the latter is set. The tool supportmay take the form of a casing packer set by means of a wire line device,or, when the bottom-most portion of the hole is to be investigated, thebottom of the hole itself may constitute the support for the tool. Afterthe tool has been set, the well is allowed to produce until conditionsof natural flow have been attained, said flow being from the variousstrata traversed by the here through the particular cell or cells whichcommunicate with such strata via one or more perforations 1'7, and intoconduit 19 via one of perforations 21. The water-sensitive materialwithin each cell is thus contacted with the effluent from the particularstratum with which the cell is in communication. Upon subseqquentwithdrawal of the tool from the bore, examination of the material ineach cell will determine Whether any fluid at all has entered the celland if so whether it is water or oil. Since the distance of each cellabove tool support 16:: and the location of the tool support withrespect to the portion of the formation over which the tool extended areboth known, the location of the oiland water-bearing strata within thatportion of the formation can readily be determined. Thus, with referenceto Figure 1, let it be assumed that supporting ring 16a is positioned ata depth of 1600' and that each of the seven cells illustrated is 1 high.When the tool is removed from the bore and the contents of each cell areexamined, it will be found that water has entered the first, fifth andsixth cells (numbering from the top), oil has entered the third andseventh cells, and the second and fourth cells will be dry. Accordingly,it is determined that waterbearing strata occur at l593- 1594 feet andat 1597-1599 feet and that oil-bearing strata occur at 1595-1596 feetand at l5991600 feet. It will be understood that the foregoingconsiderations are illustrative only, and do not necessarily representthe conditions in an actual producing formation; usually the producinginterval extends over a much greater length of the well bore and thetool empioyed will provide for considerably more than seven cells. Also,it will be understood that the apparatus may be adapted to indicateoilor gas-bearing strata by employing an oilor gas-sensitive indicatingmaterial in the spaces between separators 2%, i. e., a material whichundergoes an observable physical or chemical change when contacted withoil or gas.

The apparatus of the present invention may be employed as a pluggingtool in several ways. For example, after the location of thewater-bearing strata ha been determined as described in the precedingparagraph, the water-sensitive material is removed from between theseparators, and in those cells which were opposite the oilbearing stratait is replaced by an impermeable material such as cement. The tool isthen run back in the bore to its former position, and a liquid pluggingagent, e. g., cement slurry, a resin-forming liquid, etc., is pumpeddown conduit 19. The liquid plugging agent will pass through thosespaces which are opposite the water-bearing strata and will flow outinto such strata through perforations 17. Pressure is maintained on thewell until the plugging agent solidifies to form a water-impermeableplug within the water-bearing strata, after which the pressure isreleased and the tool is removed from the bore leaving the water-bearingstrata completely plugged and the oil-bearing strata in freecommunication with the bore hole. The well is then placed in productionin the conventional manner.

According to an alternative mode of operation, the tool is positioned inthe bore hole as above described and the well is allowed to produceuntil equilibrium conditions are established. The tool is then withdrawnfrom the bore and the water-sensitive material is removed from betweenthe separators and examined. Those spaces through which water haspassed, as indicated by the con dition of the water-sensitive materialcontained therein, are then plugged off with a water-impermeable solidsuch as cement or a resinous plugging agent, and the remaining spacesare left open. The tool is then relocated in the bore and the well isplaced in production. As will readily be apparent, the fluids from theoil-bearing strata pass freely through the open cells into the centralconduit of the tool whereas the fluids from the water-bearing strata areexcluded by the impermeable plug in the cells which lie opposite suchstrata. According to this mode of operation, the tool remainspermanently within the bore and forms a permanent part of the tubingstring.

According to a third mode of operation, the watersensitive materialwhich fills the spaces between separators 20 is of a type which isunaffected by oil but which swells or otherwise changes upon contactwith water or brine to form a water-impermeable plug. The tool is runinto the bore and positioned opposite the formation to be treated asabove described, and the well is placed in production. In those cellsinto which water passes from water-bearing strata, the water-sensitivematerial will form the aforesaid water-permeable plug, thereby shuttingoff the flow of water into the central conduit, whereas the flow of oilfrom the oil-bearing strata into the central conduit is unimpaired. Asin the mode of operation described in the preceding paragraph, the toolremains in the well as a permanent part of the tubing string.

Referring now to Figure 2, which illustrates one specific embodiment ofthe invention, the device therein shown consists of a centrallongitudinal conduit 30 which may be provided with means, not shown, forcoupling to a well tubing string. Separators 31 are spaced along thelength of conduit in spaced pairs, the uppermost separator being weldedor otherwise aflixed to conduit 30, as at 32, but the remainingseparators being free to slide along conduit 30. The lowermost ofseparators 31 is retained on conduit 30 by a pin or other clamping means33 which holds the entire assembly together while the device is beinglowered into the well casing. Each separator 31 conveniently takes theform of a flat disc having a center hole corresponding closely to theoutside diameter of conduit 30 and having a diameter somewhat, say /2",less than that of the internal diameter of the well casing in which thetool is to be employed. The latter is designated by dotted lines 34.Resilient sealing means 35, in the form of a flat disc having a centerhole closely corresponding to the outside diameter of conduit 30 and adiameter corresponding closely to the inside diameter of casing 34,occupies the space between each two separators 31 which constitute apair. Said means are conveniently formed of oil-resistant rubber or thelike, and upon being compressed expand in a lateral direction. Each pairof separators 31 is separated, one pair from the other, by a cylindricalshell or tube 36 which is of substantially the same outside diameter asthat of separators 31 and which engages opposed separators 31.Preferably the edges of shells 36 and the faces of separators 31 aremachined so that a fluid-tight seal is formed upon mere frictionalengagement, thereby simplifying the assembly and disassembly of theapparatus, but if desired shells 36 may be positively sealed toseparators 31, as by welding. Shells 36 are provided with lateralperforations 37, and conduit 30 is provided with similar perforations 38between each pair of separators 31. A foramin-ous fluid-sensitivematerial 39 substantially fills the spaces between the pairs ofseparators 31. As will readily be seen, the tool illustrated by Figure 2in essence consists of a longitudinal stack of isolated cells orchambers, each of which is defined by imperforate end portionsconstituted by opposed separators 31, a perforate outside wallconstituted by shell 36, and a perforate inner wall constituted by aportion of conduit 30, each substantially filled with a fluid-sensitivematerial '39, and each separated from its adjacent cell or chamber byresilient sealing means in the form of a septum.

Figure 3 illustrates the device of Figure 2 positioned within a wellbore. Tool support 40 is welded or otherwise afiixed to the inside ofwell casing 34 which has been perforated as at 41, and the device ofFigure 2 has been run down the casing until the lowermost of separators31 rests on support 4d. When the full weight of the device and/or thewell tubing to which it is coupled rests on tool support 40, resilientsealing means 35 are compressed and expand laterally to form fluid-tightseals with the well casing as at 42. Thus, the well bore is dividedlaterally into a plurality of isolated cylindrical chambers ofrelatively short length, and the total flow of fluid into the bore issubdivided into separate streams, each of which passes via perforations41and 37 through a body of fluid-sensitive material 39 and into conduit30 via perforations 38. As has been previously explained, subsequentexamination of the fluid-sensitive material in each of the chambers willestablish the aqueous, oleaginous or gaseous nature of the stream offluid which has passed therethrough, and the location of each streamwith respect to the location of tool support 40 is readily determinedfrom the dimensions of the particular device employed.

Figure 4, to which reference is now made, represents another form whichthe apparatus of the invention may take. Central longitudinal conduit 50carries conical wedges or cams 51 having their apexes directeddownwardly spaced at intervals along its length. Said wedges may beintegral with conduit 50, as shown, or may take the form of conicalcollars affixed to conduit 50, as by welding. Resilient sealing means 52take the form of relatively thick circular discs having a diameterslightly less than the inside diameter of the well casing in which thedevice is to be employed (indicated by dotted line 53) and beingprovided with a center hole having a diameter slightly larger than theoutside diameter of conduit 50. Each of sealing means 52 is mounted onconduit 50 immediately below each of wedges 51 so that the apex of thelatter is in register with the central hole of sealing means 52'.Cylindrical shells 54- h-aving a diameter slightly less than that ofsealing means 52 and having perforations 55 extending laterally throughtheir walls extend between the opposed faces of adjacent sealing means52, and register in peripheral grooves 56 cut in the faces of sealingmeans 52. Bottom plate 57 is 'aflixed at the lower end of conduit 50, asby welding at 58, and serves as clamping means to hold the assemblytogether. Perforations 59 extend laterally through the walls of conduit50 between wedges 51. The device of Figure 4 thus takes the form of aseries of isolated fluid-tight cylindrical chambers strung along thelength of conduit 50, each of said chambers being defined by the opposedfaces of adjacent sealing means 52, the inner wall of a perforatecylindrical shell 54, and the outer wall of perforate conduit 50. Eachof said chambers is filled with a fluid-sensitive material 60 which ispacked loosely enough to permit longitudinal movement of conduit 50 andattached wedges 51.

Figure shows the device of Figure 4 in operating position withinperforated well casing 53. The lowermost of sealing means .52 rests ontool support 61 afiixed inside casing 53. Conduit 5d has been moveddownwardly with respect to sealing means 52 and shells 54, said movementbeing effected either by the force of gravity acting on conduit 50 and/or the tubing string to which it is attached at its upper end, or by apositively applied pressure. Said downward movement forces wedges 51into the center holes of sealing means 52, thereby causing the latter toexpand laterally and contact well casing 53 at their peripheries to formfluid-tight seals therewith. The well bore is thus divided verticallyinto a series of chambers, each of which is in communication withconduit 50 via perforations S9 and With. the subterranean formationopposite which the tool extends via perforations 55 in shells 54 and theperforations in casing 53. The flow of fluids from said formation isthus caused to be subdivided by horizontal planes into a number ofstreams, each of which flows into conduit 50 through one or more of thechambers formed by the tool and affecting (or not affecting) thefluid-sensitive material 60 contained in each of said chambers. As haspreviously been explained, subsequent inspection of the sensitivematerial in each of said chambers est blishes the aqueous or oleaginousnature of the fluid which has flowed therethrough, and the location ofthe source of said fluid can accurately be determined. As will readilybe apparent wedges 51 may be tapered upwardly and the central holes ofsealing mean 52 so in register therewith that lateral expansion of thesealing means is effected by raising conduit 50 and attached wedges 51with respect thereto.

Referring now to Figures 6 and 7, there is there shown a form of devicein which hydraulic or pneumatic means areemployed to seal off the borehole into a plurality of chambers containing a fluid-sensitive material.Longitudinal conduit 70 has separators 71 rigidly afiixed along itslength in spaced pairs. A cylindrical shell 72 having perforations 73extending through its walls extends between adjacent pairs of separators71 and forms fluidtight seals therewith at its upper and lower edges.Sealing means 74 occupies the space between each two separators 71 whichtogether constitute one of said spaced pairs, and takes the form of aflat inflatable hollow disc having relatively thin walls constructed ofa resilient material such as rubber. The outer diameter of sealing means74 in a deflated condition is somewhat less than the inside diameter ofthe well casing 75 in which the tool is to be employed. Each of saidsealing means has a center hole through which conduit 70 extends and issealed to conduit 70 at the edges of said hole. Each sealing means thusresembles a tubeless automotive pneumatic tire mounted on conduit 70between each two separators '71 which form a pair. Hydraulic orpneumatic line 76, which is connected with a source of gas or liquidpressure, not shown, runs substantially parallel to conduit 70 andcommunicates via ports 77 to the hollow interior of each of sealingmeans 74. Conduit 76 is provided with lateral perforations '78 betweeneach pair of separators 71, and the spaces bounded by adjacent pairs ofseparators 71, shells 72, and conduit 70 are filled with afluid-sensitive material 79. The device is positioned in casing '75 aspreviously described and gas or fluid pressure is applied to line 76,thereby inflating sealing means 7d and causing them to expand laterallyto meet and form fluid-tight seals with the inside wallof casing '75 attneir peripheries. The device is thereafter operated as an indicatingand/or plugging tool as hereinbefore explained.

As will be apparent to those skilled in the mechanical arts, manymodifications othcr than those explained above may be made withoutdeparting from the scope of the invention. For example, each of thedevices described above comprises perforate shells coaxial with thelongitudinal conduit and extending between the spaced sealing means orbetween spaced pairs of separators which contain the sealing means.Since the purpose of such shells is in some instances merely one ofcontaining a particulate non-self-supporting fluid-sensitive materialwithin the confines of the device, such shells may in those instances bedispensed with where the fluid-sensitive material is sufliciently rigidas to be self-supporting. In other cases, as in the device of Figures 2and 3, such shells serve the further purpose of effecting operation ofthe sealing means and cannot be dispensed with. In essence, the deviceof the invention comprises a perforate longitudinal conduit, a pluralityof disc-like sealing means ooa-xially spaced along the length of saidconduit and sealed thereto in substantially fluid-tight relationship,said sealing means being capable of being extended laterally to contactat their peripheries the inner wall of a well casing and formfluid-tight seals therewith, means for efiectmg said extension of saidsealing means, and a foraminous fluid-sensitive material positioned inthe spaces between said sealing means and exterior of said conduit.

The fluid-sensitive material which is referred to herein may take a widevariety of forms, it being necessary only that such material be at leastinitially permeable to water, oil and gas and undergoes some observablephys- 1cal or chemical change upon being contacted with water, oil orgas. in most instances, the device of the invention will be employed forlocating and plugging water or brine strata, and the material inquestion need be sensitive only to water. For example, it may consistsimply of silica sand which will absorb or adsorb sufficient water orbrine to change its electrical conductivity, or it may be a porousmineral or cellulosic material which is impregnated with a chemical saltor dye which changes color upon becoming wet with water. Certain cobaltsalts, for example, are blue when dry and pink when Wet. Fatty acids,soaps and other oil-soluble materials may be employed to indicate thepresence of oil. Highly absorptive materials such as silica gel oractivated charcoal may be employed since the fluids adsorbed thereon, bethey water, oil or gas may be driven off by heating and their quantityand nature determined by conventional means of chemical analysis.According to one embodiment of the invention, the material in questionis one which is permeable to oil but which swells upon contact withwater or brine to form a water-impermeable plug. Colloidal clays havethis property, as do certain cellulose derivatives, and either may beemployed. A particularly suitable material of this nature consists of amixture of white pine sawdust and carboxymethylcellulose. For example, aloosely packed 50-50 mixture of ZO-mesh white pine sawdust andcarboxymethylcellulose is highly permeable to oil but upon beingcontacted with water or brine swells to form a soft semi-solid which hasa permeability with respect to water of substantially zero. Othermaterials of this nature include wood fiber and combinations thereofwith bentonite or the like, ethylcellulose, methylcellulose, peat moss,foaming cement (such as a mixture of Portland cement and aluminumpowder), paper pulp, aerosol-treated wood fiber, etc. As previouslynoted, the sensitive material may be particulate andnon-self-supporting, or it may take the form of a porous integral solid.

Other modes of applying the principle of our invention may be employedinstead of those explained, change being made as regards the means orelements employed, provided the apparatus stated by any of the followingclaims, or the equivalent of such stated apparatus, be produced.

We, therefore, particularly point out and distinctly claim as ourinvention:

1. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said bore; a plurality ofresilient fluid-tight sealing members coaxially spaced along the lengthof said body member in fluid-tight relationship therewith, each of saidsealing members having a normal diameter less than that of the well borein which the device is employed but capable of lateral expansion to forma substantially fluidtight seal at its periphery with the walls of saidbore to partition said formation into a plurality of isolated sectionscommunicating with said passage in said body member via at least one ofsaid ports; means for so expanding said sealing members; and aforaminous fluid-sensitive material contained exterior of said bodymember in the spaces between said sealing members.

2. A device as defined in claim 1 wherein said foraminousfluid-sensitive material is a material which undergoes an observablephysical or chemical change upon being contacted with aqueous media.

3. A device as defined in claim 1 wherein said foraminousfluid-sensitive material is a material whose per.- meability withrespect to aqueous media is substantially decreased upon being contactedwith such media but its permeability with respect to mineral oil issubstantially unafiected upon being contacted with mineral oil.

4. A device as defined in claim 1 wherein the said foraminousfluid-sensitive material is a mixture of sawdust andcarboxymethylcellulose.

5. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said bore; a plurality ofresilient fluid-tight sealing members coaxially spaced along the lengthof said body members in fluid-tight relationship therewith, each of saidsealing members having a normal diameter less than that of the well borein which the device is employed but capable of lateral expansion to forma substantially fluidtight seal at its periphery with the walls of saidbore to partition said formation into a plurality of isolated sectionscommunicating with said passage in said body member via at least one ofsaid ports; means for so expanding said sealing members; perforatetubular members mounted coaxially with and spaced away from said bodymember and extending between adjacent sealing members; and a forarninousfluid-sensitive material contained between said tubular members and saidbody member in the spaces between said sealing members.

6. A device as defined in claim 5 wherein the said foraminousfluid-sensitive material is a material which undergoes an observablephysical or chemical change upon being contacted with aqueous media.

7. A device as defined in claim 5 wherein the said foraminousfluid-sensitive material is a material whose permeability with respectto aqueous media is substantially decreased upon being contacted withsuch media but whose permeability with respect to mineral oil issubstantially unaffected upon being contacted with mineral oil.

8. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a Well bore opposite afluid-producing formation traversed by said bore; a plurality ofresilient fluid-tight sealing members coaxially spaced along the lengthof said body member in fluid-tight relationship therewith, each of saidsealing members having a normal diameter less than that of the well borein which the device is employed but capable of lateral expansion to forma substantially fluidtight seal at its periphery with the walls of thebore to partition said formation into a plurality of isolated sectionscommunicating with said passage in said body member via at least one ofsaid ports; means for so expanding said sealing members; relativelyrigid means positioned above and below each of said sealing members tominimize longitudinal expansion thereof; and a foraminousfluid-sensitive material contained exterior of said body member in thespaces between said sealing members.

9. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said bore; a plurality ofresilient fluid-tight sealing members coaxially spaced along the lengthof said body member in fluid-tight relationship therewith, each of saidsealing members having a normal diameter less than that of the Well borein which the device is employed but capable of lateral expansion to forma substantially fluidtight seal at its periphery with the Walls of thebore to partition said formation into a plurality of isolated sectionscommunicating with said passage in said body member via at least one ofsaid ports; means for so expanding said sealing members; relativelyrigid means positioned above and below each of said sealing members tominimize longitudinal expansion thereof; perforate tubular membersmounted coaxially with and spaced away from said body member andextending between adjacent sealing members; and a foraminousfluid-sensitive material contained between said tubular members and saidbody member in the spaces between said sealing members.

10. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said bore; a plurality ofresilient fluid-tight sealing members coaxially spaced along the lengthof said body member in fluid-tight but longitudinally movablerelationship therewith, each of said sealing members having a normaldiameter less than that of the well bore in which the device is employedbut capable of lateral expansion to form a substantially fluid-tightseal at its periphery with the walls of said bore to partition saidformation into a plurality of isolated sections communicating with saidpassage in said body member via at least one of said ports; relativelyrigid supporting members having a diameter less than that of said wellbore coaxially mounted along the length of said body member immediatelyabove and below each of said sealing members, the uppermost only of saidsupporting members being aflixed to said body member; coaxial perforatetubular members having an inside diameter less than that of saidsupporting members but substantially greater than the outside diameterof said body member extending between adjacent supporting members in thespace between adjacent sealing members; clamping means aflixed to saidbody member below the lowermost of said supporting members; and aforaminous fluid-sensitive material contained in the spaces between saidtubular members and said body member.

11. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral parts communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a Well bore opposite afluid-producing formation traversed by said bore; a plurality of taperedwedges coaxially aflixed to said body member in spaced relationshipalong the length thereof; a plurality of resilient fluid-tight sealingmemberscoaxially spaced along the length of said body member, each ofsaid sealing members having a normal diameter less than that of the wellbore in which the device is employed but capable of lateral expansion toform a fluid-tight seal at its periphery with the walls of said bore topartition said formation into a plurality of isolated sectionscommunicating with said passage in said body member via at least one ofsaid ports, and each of said sealing members having a center openinglarger than the outside diameter of said body member and in registerwith the narrow ends of said tapered wedges; perforate tubular membersmounted coaxially with and spaced away from said body member andextending between adjacent sealing members; clamping means for retainingsaid sealing members on said body member; and a foraminousfluid-sensitive material contained between said tubular members and saidbody member in the spaces between said sealing members.

12. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said well bore; a plurality ofhollow inflatable sealing members coaxially spaced along the length ofsaid body member in fluid-tight relationship therewith, the diameter ofsaid sealing members when deflated being less than that of the well borein which the device is employed but such that upon inflation saidsealing members engage the walls of said Well bore and formsubstantially fluid-tight seals therewith and thereby partition saidformation into a plurality of isolated sections communicating with saidpassage in said body member via at least one of said ports; relativelyrigid means for restricting longitudinal expansion of said sealingmembers upon being inflated; means for inflating said sealing members;and a foraminous fluid-sensitive material contained exterior of saidbody member in the spaces between said sealing members.

13. An indicating and plugging device for use in well bores comprising,in combination, an elongated body member having a continuous passageextending therethrough and vertically spaced lateral ports communicatingbetween said passage and the exterior of said member, said body memberbeing adapted to be positioned within a well bore opposite afluid-producing formation traversed by said well bore; a plurality ofhollow inflatable sealing members coaxially spaced along the length ofsaid body member in fluid-tight relationship therewith, the diameter ofsaid sealing members when deflated being less than that of the well borein which the device is employed but such that upon inflation saidsealing members engage the walls of said well bore and formsubstantially fluidtight seals therewith and thereby partition saidformation into a plurality of isolated sections communicating with saidpassage in said body member via at least one of said ports; relativelyrigid means for restricting longitudinal expansion of said sealingmembers upon being inflated; perforate tubular members mounted coaxiallywith and spaced away from said body member and extending betweenadjacent sealing members; means for inflating said sealing members; anda foraminous fluid-sensitive material contained between said tubularmember and said body member in the spaces between said sealing members.

References Cited in the file of this patent UNITED STATES PATENTS

